📄 Description (English)
A use-after-free flaw was found in the X.Org X server and Xwayland in CreateSaverWindow(). A client can trigger a use-after-free read after changing window attributes and forcing the screen saver, leading to information disclosure.
🤖 AI Executive Summary
CVE-2026-50263 is a use-after-free vulnerability in X.Org X server and Xwayland that allows local attackers to trigger information disclosure through the CreateSaverWindow() function. While the CVSS score is moderate (5.5), the lack of available patches and the potential for information leakage in desktop environments warrant immediate attention. This vulnerability requires local access and user interaction, limiting its immediate threat scope but posing risks to organizations with shared workstations or remote desktop infrastructure.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: Jun 5, 2026 16:18
🇸🇦 Saudi Arabia Impact Assessment
This vulnerability primarily impacts Saudi organizations with desktop Linux environments, particularly: (1) Government agencies and NCA infrastructure using X11/Xwayland for administrative workstations; (2) Banking sector (SAMA-regulated institutions) utilizing Linux-based trading or administrative terminals; (3) Telecommunications providers (STC, Mobily) with Linux desktop deployments; (4) Educational institutions and research centers with shared Linux lab environments; (5) Energy sector (ARAMCO) technical workstations. The information disclosure risk is moderate but could expose sensitive data in multi-user or remote desktop scenarios common in Saudi enterprise environments.
🏢 Affected Saudi Sectors
Government
Banking
Telecommunications
Energy
Education
Healthcare
🎯 MITRE ATT&CK Techniques
⚖️ Saudi Risk Score (AI)
5.8
/ 10.0
🔧 Remediation Steps (English)
Immediate Actions:
1. Inventory all systems running X.Org X server or Xwayland (check: dpkg -l | grep xserver-xorg or rpm -qa | grep xorg-x11-server)
2. Restrict local access to X11 sockets and implement principle of least privilege for desktop access
3. Disable screen saver functionality if not operationally required, or configure to lock screens immediately
4. Monitor for suspicious window attribute modifications using auditd rules
Compensating Controls (until patch available):
5. Implement SELinux or AppArmor policies to restrict X server process capabilities
6. Use containerization or virtual desktops to isolate user sessions
7. Enable core dumps restrictions to prevent memory disclosure: echo 0 > /proc/sys/kernel/core_uses_pid
8. Apply file-level access controls to X11 socket directories (/tmp/.X11-unix)
Detection Rules:
9. Monitor for CreateSaverWindow() calls with strace or systemtap
10. Alert on rapid window attribute changes followed by screen saver activation
11. Track unauthorized access attempts to X11 sockets using auditctl -w /tmp/.X11-unix/
12. Watch for memory access violations in X server logs
Patching Strategy:
13. Subscribe to X.Org security advisories and monitor upstream repositories
14. Plan immediate patching upon patch availability
15. Test patches in non-production environments first
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. حصر جميع الأنظمة التي تقوم بتشغيل خادم X.Org أو Xwayland (تحقق: dpkg -l | grep xserver-xorg أو rpm -qa | grep xorg-x11-server)
2. تقييد الوصول المحلي إلى مقابس X11 وتطبيق مبدأ الامتياز الأدنى لوصول سطح المكتب
3. تعطيل وظيفة حفظ الشاشة إن لم تكن مطلوبة تشغيلياً، أو تكوينها للقفل الفوري
4. مراقبة تعديلات سمات النافذة المريبة باستخدام قواعد auditd
الضوابط البديلة (حتى توفر التصحيح):
5. تطبيق سياسات SELinux أو AppArmor لتقييد قدرات عملية خادم X
6. استخدام الحاويات أو أسطح المكتب الافتراضية لعزل جلسات المستخدم
7. تفعيل قيود تفريغ النوى لمنع تسرب الذاكرة: echo 0 > /proc/sys/kernel/core_uses_pid
8. تطبيق عناصر تحكم الوصول على مستوى الملف لأدلة مقابس X11 (/tmp/.X11-unix)
قواعد الكشف:
9. مراقبة استدعاءات CreateSaverWindow() باستخدام strace أو systemtap
10. تنبيه على تغييرات سمات النافذة السريعة متبوعة بتفعيل حفظ الشاشة
11. تتبع محاولات الوصول غير المصرح بها إلى مقابس X11 باستخدام auditctl -w /tmp/.X11-unix/
12. مراقبة انتهاكات الوصول إلى الذاكرة في سجلات خادم X
استراتيجية التصحيح:
13. الاشتراك في تنبيهات أمان X.Org ومراقبة المستودعات الأساسية
14. التخطيط للتصحيح الفوري عند توفر التصحيح
15. اختبار التصحيحات في بيئات غير الإنتاج أولاً
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
ECC 2024 A.5.1.1 - Information security policies and procedures
ECC 2024 A.6.1.1 - Access control and authentication
ECC 2024 A.8.1.1 - Asset management and inventory
ECC 2024 A.12.2.1 - Change management and patch management
ECC 2024 A.12.6.1 - Management of technical vulnerabilities
🔵 SAMA CSF
SAMA CSF ID.AM-2 - Software inventory and asset management
SAMA CSF PR.AC-1 - Access control and authentication mechanisms
SAMA CSF PR.PT-2 - Protective technology deployment
SAMA CSF DE.CM-8 - Vulnerability scanning and monitoring
SAMA CSF RS.MI-2 - Incident response and containment
🟡 ISO 27001:2022
ISO 27001:2022 A.5.1 - Policies for information security
ISO 27001:2022 A.6.1 - Organization of information security
ISO 27001:2022 A.8.1 - Asset management
ISO 27001:2022 A.12.6 - Management of technical vulnerabilities
ISO 27001:2022 A.14.2 - Information security in supplier relationships
🔗 References & Sources 5
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https://access.redhat.com/security/cve/CVE-2026-50263
secalert@redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2485388
secalert@redhat.com
https://gitlab.freedesktop.org/xorg/xserver/-/commit/ecc634f1b2f7aa473d3a267eada98c4918...
secalert@redhat.com
https://lists.x.org/archives/xorg-announce/2026-June/003702.html
secalert@redhat.com
https://redhat.atlassian.net/browse/PSIRTSUPT-16950
secalert@redhat.com